As the photoacid generator for use in chemically-amplified photoresists, color filters for liquid crystal and the like, paramethoxystyryl triazine has been conventionally known (see, for example, G. Pohlers et al, “Chem. Mater.”, 1997, 9(6), pp. 1353-1361).
Although paramethoxystyryl triazine is highly sensitive, it is disadvantageous in terms of unfavorable solubility and compatibility with a solvent.